Technical Field
The present disclosure relates to a vehicle side door structure.
Related Art
International Publication (WO) No. 2011/010370 describes an invention relating to a vehicle side door structure. In this vehicle side door structure, an acceleration sensor is provided to a side door. The acceleration sensor is configured so as to output a signal according to acceleration in the vehicle width direction, and this signal is output to an airbag ECU. When localized collision load is input to the side door and the signal input to the airbag ECU from the acceleration sensor is a threshold value or greater, the airbag ECU actuates a side airbag device. Thus, an occupant is protected against the side door intruding inner side a vehicle cabin by an inflated and deployed side airbag.
However, when the occupant is protected by the side airbag device, the side airbag needs to be inflated and deployed in a narrow gap between a vehicle width direction outer side side area of the occupant and the side door. Thus, it is preferable to secure as long a usable time as possible in order to deploy the side airbag, and it is therefore desirable that the collision load can be transmitted to the acceleration sensor detecting a collision at an early stage.
Regarding this point, the vehicle side door structure described in WO No. 2011/010370 is configured such that collision load is transmitted to the acceleration sensor at an early stage using a sensing bracket. Specifically, in this vehicle side door structure, a portion at the vehicle width direction outer side of a door main body configures an outer panel, a portion at the vehicle width direction inner side of the door main body configures an inner panel, and an internal space is formed between the outer panel and the inner panel. In this internal space, a straight impact beam is disposed extending along the vehicle front-rear direction at the vehicle width direction inner side of the outer panel, and the sensing bracket is disposed attached to the inner panel at the vehicle width direction inner side of the impact beam. The acceleration sensor is attached at the vehicle cabin inner side of the inner panel. Thus, when localized collision load is input to the outer panel of the side door, the outer panel is pressed and deformed, and collision load is input to the impact beam through the outer panel. A length direction intermediate portion of the impact beam that has been input with collision load bends toward the vehicle width direction inner side, accompanying which the outer panel locally approaches the inner panel side, and the sensing bracket is pressed by the outer panel. Thus, collision load is transmitted to the sensing bracket, and collision load transmitted from the sensing bracket to the inner panel is input to the acceleration sensor attached to the inner panel. Thus, the above related art enables collision load input to the outer panel to be transmitted at an early stage to the acceleration sensor through the sensing bracket.
However, in the case of the above related art, there is a relatively wide space between the outer panel and the impact beam, such that a time lag (namely, free-movement time of the outer panel) arises between the start of deformation of the outer panel and the start of deformation of the impact beam. In particular, the outer panel gently curves toward the vehicle width direction outer side in many vehicle types, such that an even wider gap is formed between the outer panel and the impact beam, this being a factor in the time lag between the start of deformation of the outer panel and the start of deformation of the impact beam. There is accordingly room for improvement with respect to transmitting collision load at an earlier stage to the acceleration sensor.